I haven't seen a clear ruling of this anywhere. RAW (in the errata) seems to indicate, that this is not possible (you could argue that the ship / group is targeted even if the card is annulled by the Espionage card).

However, RAI seems to be, that you want to prevent/limit people from stacking effects from multiple cards to create something with too strong a synergy. Seen from that perspective you should be allowed to target a group again if the first card was espionaged.

I had a question about command card stacking as well. The FAQ is a bit confusing, can you stack battlegroup cards and fleet cards? ie can I play two cards that target battlegroups on the same battle group or play two cards that target the entire fleet.

in the answer part of the faq it states

Ships may be affected by battlegroup, fleet wide or ‘area’ affects several times per turn as they are not specifically targeted at that ship or group, meaning they can stack with specifically targeted cards on individual ships or groups

which suggests to me that you can play multiple cards that target battlegroups (or fleetwide)

but just after it says

More specifically:Command cards may not be stacked ship on ship, group on group, or any combination of these. They may also not be stacked or battlegroup on battlegroup(sic), but may otherwise be stacked.

which tells you (kind of) you cant stack battlegroup targeting cards but doesnt mention fleetwide cards (although seems to be a typo)

and in the example part it states

If you play a command card on a battlegroup, you may not play another command card that targets that battlegroup this turn. However, you may play command cards that target specific ships or groups in that battlegroup (applying the above restrictions about stacking command cards on ships and groups).If you play a command card that targets the entire fleet, you may not play another command card that targets the entire fleet this turn.

which tells you that you cant stack fleetwide with fleetwide or battlegroup with battlegroup cards.

which bit of the faq do we go by, I'm guessing the example is the correct part? its been causing some confusion in my group, not helped by the example part of the question being on a different page to the answer part in the pdf leading to different interpretations when quickly searching for the answer mid-game.

So basically, certain command cards MAY affect ships in an entire battlegroup or group at the same time. So for example with UCM.

I could play Mass Driver Volley, which affects "all ships in a Battlgroup". For example, we'll say 2 Moscows.

Then I could play Orbital Targeting Matrix which affects "one Friendly Group" in a Battlegroup. Which I can target the Moscows with as previously the Moscows were only affect by a card which stated whole Battlegroup

Then I could play Re-Calibrated Targeting which "affects One ship" so I simply pick one of the Moscows to use it on.

But what you cannot do is play Ships of the Reconquest on the 2 Moscows Battlegroup, if you have previously played Super Numbers on the Moscows Battlegroup as both cards the Target is "One Friendly Battlegroup"